Hydraulic crowder



K. MEvsslcK 1,937,432

Nov. 28, 1933.

HYDRAULIC cnowDER Filed Aug. 26, 1931 '5 Sheets-Sheet l Nov. 2s, 1933. K. MEsslcx 1,937,432

HYDRAULIC CROWDER Filed Aug. 26, 1931 5 Sheets-Sheet 2 gvmwnoz E 'wa/z Messick.

zfw, MW 4MM Nov. 28, 1933. K, MEsslCK 1,937,432

l HYDRAULIC cRowDER Filed Aug. 26 I1931 3 Sheetsr-Sheet 3 Messick.

Patented Nov. 28, 1933 1,937,432 HYDRAULIC CEOWDER Kirwan Messick, Clarendon, Va.

Application August 26, 1931. Y Serial No. 559,533

4 claims. v- V(c1. 214-135) The present invention relates to excavating machinery and more particularlyto a hydraulic drive to be used in connection with the crowding or thrusting mechanism of said power excavators 5 having among its principalobjects to improve the power efficiency and operation, closely approaching steam for Crowder drives, obviating the necessity for gearing, difculties commonly experienced with steam driven crowders, as well as air driven crowders, in that there is no possibility of freezing of the uid employed as is common in air driven crowders, when the machines are used in frigid regions. i Another object of the present invention is tol5` provide an independent crowding mechanism for power driven excavators, which is solely carried by and mounted upon the boom of the excavator, independent, because itis not directly connected with the other driven mechanisms of the ex-y cavator and mounted upon and carried by the boom not only because of the saving of space within Athe cab ofthe excavator but because .of the fact that a boom lhaving any of the prevailing Itypes of excavating implements carried thereby may be readily connected tothe excavator whereby the excavating machine may be selectively converted into a trench hoe, skimmerscoop, dipper bucket,v or the like excavator, or it may be selectively converted into `a, pile driver,

' 30 derrick, or crane.

A further object of the present invention isto provide a hydraulick drive system for excavating machinesV of the character heretofore mentioned which is so designed that the prime rnlover,`

whether it be an internal combustion engine, or an electric motor, need only be of such capacity as to carry the average load of the boom and shovel hoisting mechanism therefor, as at no time does the load of the crowding operation act directly upon the prime mover, thereby accomplishing the maximum amount of work with a minimum amount of power.

In the hydraulic drive system embodying the present invention, I provide a prime Vmover for driving a pump of the rotary' type which latter, during its continuous operation, causes to be stored up ina suitable reservoir or tank, fluid, preferably oil, under pressure and the fluid so stored within this pressure tank is fed to asingle or double acting hydraulic motor arranged upon the boom 4of. the excavator and connected to the dipper stick thereof by means of -Wire ropes or cables. The oppositelends of lthese cables are aixed to the dipper` stick and boom through 55 suitable shock absorbers, -thereby cushioning the clutches, toggles,v brakes, and

isible embodiments of the same.

shock tothe cables or ropes andtheir respective i motors, when the thrusting or reversing `action takes place. Theprime mover also beingthrough a suitable mechanical drive connection, is"con nected tothe boom and shovel hoisting meansgsov 6l)N thatwhen the crowding mechanism is in operation, the full power of the prime mover maybe utilized foroperating the boom or shovelhoisting mechanism. When the hoisting mechanism is.

at rest, the system is so arranged asto permit the prime mover to cause power to be storedwup 'in the fluid pressure tank and, therefore, it fisf a kstill further obj`v e `ct of the present invention 'to provide a control means for hydraulic drive systems for power operated'excavators V vsffherebI/, the 7g) prime mover will be automatically `disconnectec'l, from the hydraulic drivesystem Whenthe hoist;- ing mechanism is brought into play, and when vthe hoisting mechanism is at rest, the prime mover will be employed for storing uppower which will k be" subsequently used for'driving the .Crowder mechanism'gy y' 4 K v, 'l Y I f A rotary type of hydraulic pump is preferably employed4 lin Athe present drive system, as itre-A i quires less horsepower toV drive the same during 3g the idling period than isrequired by piston typer airkcompressors or pumps, therefore lleaving fa greater amount of horsepowerfgeneratedby the prime mover to drive the boom or bucket hoisting y mechanism.v f My improved hydraulic` drive systemY andthe general assembly of an 'excavator to befherein,

after described is` comparatively Ainexpensivefto build having but a reduced number of jointsfand` power moving parts,` such as shafts, gears, 9g l v thelike, than is required `by the mechanical drivesnow being extensively used. Due to the cableconnectionsbetweenthedipperstick and the crowderlmotors, the pistons of the latter will have a ratio operating movement of 2 to 1,` that isfeac'h piston will t" travel one foot for every two feet of travel ofithe dipper sticky, .A ,y

In order that the invention andrits'mode'l of operationrmay `bereadily understoodby persons skilled inthe art, I have, in the accompanying illustrative drawings and inthe detailed following description based thereon, set out several pos- In'these drawings: Y i

Figure l is a fragmentary' side elevationof' a conventional form ofj power driven excavator havingthe improved hydraulic crowd'.=mechal nism embodying the present ,inventiomappliedf thereto; i l, 11,10

Figure 2 is a detail view partly in section of one of the flexible connections between a cable oi the hydraulic crowd mechanism and the dipper stick ofthe excavator;

Figure 3 is a diagrammatic alV showing of the hydraulic crowd mechanism embodying the invention; Y.

. prime'rnover and the hoisting drums.

i Referring now more particularly tothe accompanying drawings wherein like corresponding parts are designated by similarreference characterslthroughout the severalviews, I have herein shownan excavator comprising a truck frame 1 mounted upon anv appropriate creeping tractor mechanism 2 and rotatably mounted vuponthis truck frame lis a cab 3 provided with the usual.

platform e." Hingedly .connected to the forward end. of this platform'eis'a boom 5` having mounted for reciprocal movement therein, a dipper stick 6v carrying at its lower end a dippe'r shovel '7;

7 of'the excavator.

Arranged upon the platform 4. of the cab is a prime mover 8 which may be a gas engine, steam engine, electric motor, or any other source of motive power necessary for operating the shovel Also" arranged .upon the platformfi of the shaft `is a drum 9 which is preferably driven by the prime mover Sand over' this drurn there extends a cable l0 of the clipper hoistk L vr"The thrusting or Ymounted upon the boom sheaveil2 connectedto the dipper whereby with or lowered. fvlie' boom 13, one end of which isA attached within the. cab

and after extending overV the shear/'elli secured Y tors being arranged siderably morev space necessary .to storeV up lthe ing'fmechanism. ,'The cable 10 hoist extends over the fair-,lead sheaves l1 rotation of thedrurn' 9, the shovel 7 may be raised hoist comprises a cable to the outer end of the boom, the opposite end Ais' attachedv to 4a winding drum 80, which'latter is alsolpropelledby. the prime mover 8. v

crowding mechanism comprisesamotor preferably mounted upon the boom 5. and fas V'this boomt nectic'nll, manyother'typesof excavating mechak ani'sm may-be connected to this cab, onejof which'beingshown in Figure 4 of the drawings and known as askirnrner-scoop. This independf ent hydraulically operated crowder for Yexcava` upon `the boom thereof not only permits the machine to be selectively -.confA verted, into other types of excavators or cranes, but makes it poss iblet o. eliminate the .mounting of complicated crowding mechanism within vthe cab' of the truck or tractor, thereby giving coninthe. cab or permitting thereduction in size thereof, and this Crowder being hydraulicallyfoperated, permits of 'the `use ofg'a prime mover .of such capacity as is' only due to theffact thatthe load Acarried Vthrough this crowdermechanismp does not .act`V directly on theprime mover. The driven shaft 1.6V of the motor 8`is connectedthrough the luniversali'coupling 17, to the 'shaft '18 of a rotary pumpl lQVand this pump 119 has communicating with its inlet port, a pipe .means of connection f or the control valve 33 and one endv of the cylinof this clipper' 5 'and` over v`another this valve 38 isin the position as is is'connectedto the platform -i, of .,the cab through the detachable coning to one' end of sure maybe supplied totheV piston 28 arranged 13() ywithin this cylinder.lr` When this valveSS'is in required fluid pressure line 2o, and with its outlet port, a pipe 21. The fluid, 'preferably oil, is stored within thereservoir 22 and flows from this reservoir 22 to the pipe 2() inthe pump. lThe fluid under pressure then passesthrough the pipe2l bya check valve 23 to a high pressure reservoir or tank 2li. A' by.- pass 25 .establishes a means of communication between the pipe lines 20 and 2l around the pump 19 andv has arranged therein a rotary valve 26 in order that when vthe valve'26 isopened and 85 the pump i9 set in motion, the fluid from the. storage tanlr 22 will be caused to circulate through this by-pass pipe' 25, but when the vvalve .dis closed,r thepump will cause the duid topass` through the pipeZi into the pressure tank or.

lreservoir 24.

For effecting the. crowding movement of the rdipper shovel 7, I preferably use tvvok motors,

The'thrusting-mof tor 27 comprises a cylinder' mounted for reciprccationtherein, whereas the retracting 1notor29 comprises a cylinder 'of small' er diameter than that`v of thezthrusting motor and having a piston 30 mounted for ieciprocation therein. A fluid'supply pipe pressure 24 and has a hand *valve 32l ar-I ranged thereinl 'his'supply pipe 3l leads to a` control valve 23. A return' pipe 3e leads from1 this control valveSS and communicates-with the storage tanl; 22. VA pipe line.35 establishes a 110 between the valvecasing der 27, and a similar'pipeline establishes 'a means or" communication between thec'ontr'ol valve and one'v end ofthe cylinderrZQa' The opt 1115 posits ends oi thesel cylinders 27 and ,29'are'in' communication vwith the return pipe' which'Y latter leads to the-storage.tank122y in vorder'that any leakage Vthat may" occur within these .cylindersV 27'and 20 around their respective pistonsy12`0 Arnayfbe caused to flowfthroughthis return pipe 371v and return to the storage tankY AI rotary valve Sais arranged within thervalvef oasingof4 the 'hand A'operatedvalve33 whereupon when shown zin 25 Figure 3 of the drawingathe iluid under pressure within the tank 24 maybe peri'nitted`V to' passv through` this valvei33 into the pipe-line .135*l'ead-V the cylinder V27, whereby. pres.-

the position ashereinf. shown, any fliqui'dj within the cylinder l29 will 'be forced by the? return of the piston 30 through the pipe line into the pipeline 34 andl subsequently to. the storage '135 Y tan-k 22. From this, 'it .isquite obvious that by rotating the valvek 38 the fluid under lpressur from the pressure 'tank'24 A may be held: against entering the pipesfl, 35 o'r 36,-but when in anotherpositicn, or that shownin Figure 3 ioflthe 14() drawings,V this fluid underpressure may be sup.

plied to the kcylinder 2'? and exhausted fromthe cylinder 29 and when'this valve' yis in athird position, the huid under pressuremay-be supplied tothe cylinder 29 andV exhausted from'thecylin- 145 der 27 where it may returnYf-rom: this cylinder 27 tothe storage tank 22, l

e The pistons 28 and '30 -n1ounted withinthe respective cylinders are each rprovided with a piston rod or stein 38 and connected to the lout- 150 having al piston '1 28 190 Silleads iromthe Y. in the "cylin'der`63 ,around thepistonarranged l therein, thisy fluid will belretu'rned to thelstorage er end ofr each stem 38 isa crosshead39 which latter, are mounted for vreciprocation within suitto the .thrusting motor 27 carries l 4whereas a sheave 42 is carriedbythe crosshead ab le guide-ways 40. The crosshead'connected a sheave4l Connected tothe retracting motor 29. A cable VV43 has one end connected as at 44 to the cylinder 429 and after passing over the sheave 42 and one of the sheaves indicated by the numeral 45 arranged upon the boom has its opposite end fixed as at 46 to the lower end of the dipper stick `6. Another Vcable 47 has one end iixedly secured as at 48 to the cylinder 27 and after extending over the sheave 41 as well asV another sheave 45 mounted upon the boom atitsopposite y end, attached to the upper en d of the dipper stick -6 as at 49. The operator when positioned within the cab 3 may, through manipulation of the lever 50, control the valve 38 whereby the iiuid under pressure may be supplied to and from the respective motors Y 27 and 29 for causing the fthrusting or crowding ofthe shovel 7 to and from its work. l

Theopposite ends of the cables 43 or 27 yare connected through a resilient connection or a shock absorben 'as is better illustrated in Figure 2 of This shock absorber comprises aA 'bracket 51, one of which is herein shown as being the drawings.

attached to each cylinder of the motors 27and 29 and upon the opposite' ends of the dipper stick 6 and has mounted for reciprocation therein a rod 52. One end of this rod 52 is threaded and receives a lock nut 53 and arranged between the brackets 5l and these lock nuts is a coil spring 54. The opposite ends ofthe cables 43 and 47 of this crowding mechanism which for convenience, are indicated in Figure 2 ofthe drawings by the numeral 56, are connected to Aa rod 52 through the swivel connection 55, and it is through this connection that the cables 43 and 47 will. at all times, be held taut and at the same time, produce acushioning eiect upon each re- Y tracting or thrusting movement of the dipper stick.

It is sometimes only necessary to provide a single motor upon the boom of the excavator when the latter is converted into a skimmerscoop such as that illustrated in 'Figure 4 of the outer end of the boom for raising the same and` when this boom is in an elevated position, this scoop 58 will be permitted to travel by gravity towards the lower end of the boom. The single motor comprising a cylinder 63 is mounted upon the boom 57 and the piston rod thereof carries a sheave 64 over which passes this cable 59 and one end of the cable 59 is attached as at 65 to the cylinder 63. A valve casing 66 is provided within the cab having connections with the pipe lines 3l and 37 of the hydraulic power supply system, whereas another pipe line 67 establishes a means of communication between the valve casing 66 and one end of the cylinder 63. Another pipe line 68 establishes a means of communication between the opposite end of this cylinder 63 and the return pipe 37 whereupon should any leakage occur withvis Yrotated through the medium tankl 22. valve 69 is arranged within thecastank orreservoir 24'to` pass into the cylin'derj ving'fio and' is controllable`A tlfirouglrthej lei/:c1530 Vwhereby the operator may byrotating, thisvalye so "69 permit theuidunder pressure in the, pressure through 'the pipeline 67 orv the Iluidsofspe'nt I,within this cylinder 63 vmay be vpermitted tofreturnthrough the pipes 67 ,and 3,7 tothe storage t'ank`22. l,When thefluid under pressure is vsupwplied to the cylindeljll,v thepiston and itsisheave whereby through thefc'able connection, 59', the scoop 58 will be thrust towards the outer end of the boom 57. in Figure 6 of the drawings, I have'disclosed the mechanical drive connectiony between/,fthe primev mover and the hoisting drum s.These hoisting drums are mounted in a conventie''naly manner upon a single driven shaft whiclilatter of the chain and sprocket connection 84 by the motor 8. The shovel or clipper hoisting cable 10 is adapted to be wound upon the drum 9 whereasvthe boom hoisting cableV 13 kis adapted to be wound `upon ythe drum 80. Through the conventionalformof clutches as herein indicatedr by thej numerals. Sil and 82, these drums 9 and 80 may be' operatively connected to the driven shaft and vthese clutches .are adapted to be controlled kby the'pp'eratcr` through theusual foot levers83.` The `valve 2 6 arranged within the by-pass 25 isprovidedwith a lever 71 and the latter may be connected to the VV rod 72 to either of the hand leversn() or 7 0 in order 'that when yeither the valve 38,01' 69 is 64 willbethrust outwardly' from this cylinder. 16,3,

opensc as to permitthe fluid underl pressure 5to travel to either one of the cylinders 27, 29 Gr.63, the valve 26 will be closed in order that the fluid passing from the pump 19 may be delivered to the reservoir 24 whereby the full powery of Vthe motor and that stored up within this reservoir 24 may be utilized for driving the hydraulic motors comprising the 'cylinder v27, 29V or .63.` I'z Through this arrangement, it is quite obvious that' Vwhen the excavator is at rest, the motor or other prime mover 8 will be continually storing upthis fluid under pressure within the reservoir 24 and should the pressure within this tank 24 begreater 'than that desired, it may pass through the pipe 73 having a release valve therein to the storage tank 22. It will'be obvious that the levers 50 or 70 which are arranged adjacent the drivers seat withinthe cab of the excavator'will jointly control the valves 26 and 38 or 69 in order thatwhen the valve 26 is open the valve 38.02'V 69 will be closed and vice Versa, in order that when the hoisting of the boom or shovel is required, the entire horsepower of the motor 8 may be utilized solely'for this purpose, but when the boom and shovel hoisting means are at rest, the motor, together with the pressure stored up within the tank 24 may be directly used for supplyingfhydraulic power to the motors of the crowd mecha'- nism. Through the continual operation of the motor S, and when the crowding and hoisting mechanisms are at rest, the uid under pressure is being 'continuously stored within -the tank 24 thereby permitting the motor, at all times, to run at a constant speed without stopping and starting the same as when the crowding or hoisting means are required for use.

From this arrangement, it willbe further apparent that theprime mover need onlybe of such capacity as to carry the average load of the boom iiio -' tractor, a powerplant v.directly upon this prime mover, the horsepower n of the latter may be greatly reduced over that required bythe conventional'type of power driven excavator. I haver-ound thatby 'using afprime mover of sufcient horsepower, at its maximum speed, will drive the hoisting means, will also have lsuflicient horsepower at its minimum speed or rwhen idling,

to operate the pump 19, thereby greatly increasing the saving of fuel consumed,

The hydraulic rotary type `of pump' Vl9'as disclosed "herein, from actual tests,

has proven that it requires less horsepower thanis required to drive vthe same during. the idling period v,oi Vthe motor than would be required i or driving the piston type air compressor or pump, vthereby accomplishing a Vvmaximum amount of Vwork with a minimum amount of power.

-"Manifestly, Vthe construction herein shown is -capable of considerable.modification and' suchl .modiiications as come within the scope of` my claims, I consider within thel spirit of my invention.

I claim: e n l. A hydraulically operated crowding mechanism for excavators comprising in combination i Y sheave carried by each piston rod, a pair of cables,

a'boom, a dipper stick slidably mounted upon Vsaid boom a pair of hydraulically operated motors arranged upon said boom, a pair of cables connecting; said motors with the opposite ends o'i'` said dipper stick, and shock absorbers arranged between the opposite ends of said cables, said dip-- per stick'and motors.

2. An excavator comprising in combination av arranged upon said'tractor, a boom detachably and. hingedly connected to said tractor, a pair of hydraulically operated motors arranged upon said boom, means whereby the power plant upon vthe tractor `may supply fluid under pressure to said hydraulically oper"V ated motors, a dipper stick slidablyl mounted Within said boom,1sliocl absorbers xedly connected to said dipper stick and motors, and cable connectionsl between 'saidadipper stick and motors whereby vwhen said motors are operated said dipper stick will be caused to move in opposite` directions uponsaidboom.

. 3. Thecombination with a boom of power driven excavators and a dipper stick mounted for Vreciprocation thereomcf apair of hydraulically opi Aerable motorsmounted directly uponv said boom,

cables connecting the opposite ends of said dipper sti'clrwith saidv motors whereby when the Y latter are set in motion", the dipper stick willV be y caused'to reciprocate upon the boom.

' 4, A crowdmechanism for power drivenjexcavators comprising in combination a boom, adipper stick mounted -for reciprocation ,within said boom, a scoop carried by one end of said dipper stick, a pair of hydraulically operable motors mounted directly upon said boomadjacent said dipper stick, each of said mctors'consistingrof a cylinder having a reciprocating piston arranged therein,` a piston rod carried by each piston, a

one end o'each cable being connectedv tosaid dipper stick, the opposite ends foi` said cables besecured to the cylinders or" said motors ing xediy. Y and said cables ypassing over said sheaves con,- nected to the piston rods of said motors, whereby ywhen the latter are set in motion, said dipper stick 

